Abstract: The aim of this study is strengthening the old wood members in historical buildings with new innovative technology, which have lost parts of their strength due to heavy loads, loading time factor, effects of extreme humidity or insects attack. Most of the ancient buildings throughout Iran have been constructed mainly by wooden members. Some of the structural members in such a valuable buildings are partially defected. Therefore, it seriously needs to be repaired or rehabilitated in order to maintain in proper strength. Present research is focused on strengthening the old wood beam members sampling from non-essential sections of historical buildings with Glass Fiber Reinforced Polymer (GFRP) composite materials. A three-point loading test was used to study the behavior of the beam subjected to gradual static load under different configurations of reinforcement. The load-displacement response, ultimate strength, modulus of elasticity and the mode of failures were evaluated. The experimental results have shown an improvement in load capacity, strength and stiffness of hybrid if compared with un-reinforced samples. At the end, the experimental and analytical results were compared with each other.